The present invention relates to a device for separating and collecting lubricating oil solved and mixed in the refrigerant in the turbo-refrigerator.
One of conventional turbo-refrigerators will be described, referring to FIGS. 1A and 1B, in which reference numeral 1 represents an evaporator, 2 a condenser, 3 a compressor, 4 a suction vane, 5 an oil reservoir in which the lubricating oil is contained, and 6 an ejector. In the case of this turbo-refrigerator, the lubricating oil which is solved and mixed in the refrigerant in the evaporator 1 is made into a mist of fine drops by boiling phenomenon in the evaporator 1, is flowed into the suction pipe of the compressor 3, and remains liquid in a space downstream the suction vane 4. The lubricating oil which remains like this is returned to the oil reservoir 5 by means of the ejector, pump (not shown) or the like.
In the case of the conventional turbo-refrigerator, however, the flow speed of the refrigerant gas which is sucked into the compressor 3 is reduced and the amount thereof is also reduced at the time when the turbo-refrigrator is operated under partial load. The amount of the lubricating oil collected from the evaporator 1 is thus decreased, while the amount of the oil left solved in the evaporator 1 is increased. The evaporative pressure of the refrigerant is thus reduced, while the pressure ratio of the compressor 3 is increased thereby causing the ratio of power consumption to be increased. Further, the amount of the lubricating oil collected is reduced, decreasing the lubricating oil in the oil reservoir 5 and causing the sucking action of the oil pump to be hindered. As a result, lubrication is made insufficient and there is fear that the compressor bearings may be broken or damaged.